TT120: HST

[Roy L S]

1 hour ago, Michanglais said:

 

It's currently running under DC, I have got some decoders so may try it on DCC. 

 

It's on flat track with R4 curves. Seems to have the same issue when on the straight as taking curves. 

 

I've tried it with a rake of 3 coaches and it runs just fine, but when I increase to 5, same issue.

 

I shall try chipping it to see if that makes any difference...

 

I am not sure why chipping the loco would make any difference to haulage capacity, surely haulage is down to just a couple of things, adequate adhesion and power which will both be the same regardless of whether DC or DCC is involved?

[woodenhead]

13 minutes ago, Roy L S said:

I am not sure why chipping the loco would make any difference to haulage capacity, surely haulage is down to just a couple of things, adequate adhesion and power which will both be the same regardless of whether DC or DCC is involved?

Add some weight to the motor power car to improve adhesion?

[Porfuera]

5 hours ago, Michanglais said:

Just wondering whether anyone else was having this problem.

 

My HST has terrible wheel-slip issues hauling a full 8-car set. It just grinds to a halt with the wheels spinning. When I detach the power car from the train, it runs just fine. 

 

I'm wondering whether it wouldn't benefit from a couple of the dreaded traction tyres. 

 

I'd like to hear pointers and opinions.

 

Cheers,

Michael

 

Hi Michael,

 

I'm sorry to say that you might want to return your HST to Hornby for them to take a look at it if fitting it with DCC doesn't cure its problems (and I'm also doubtful that it would cure it but it must be worth a try).

 

After seeing your post I thought I'd give mine a test as I currently have a running-in loop of track on my dining room table (much to the delight of the Domestic Authority). The loop is a full circle of Tillig bedding track of radius 396 (so equal to Hornby's R4) plus only four 166mm straights, laid out with two straights per side (so the circuit is an oval rather than a 'square').

 

I don't have any BG Mk3s (they're not out yet) so I tried my HST set with three unlit Pullmans from the Scotsman set and three Mk1 from the Easterner. My HST set is DCC and it came pre-fitted.

 

The 'train' was long enough to cover almost half of the circuit so a considerable amount of it is always on a curve yet it pulled away at the lowest speed setting (i.e. '1' on the app) and continued crawling at that speed without any problems for a full circuit.

 

Then I noticed that you said you were running 8 coaches rather than the six that I had. The only bogie vehicles I had left to try were three Arnold container wagons so I added those to give a total of 9 vehicles plus the dummy power car. I think the Arnold wagons are a bit heavier than the coaches, plus the 'train' now covered more than half of the circuit, so it was even more demanding. However, the result was the same with the HST starting at '1' and continuing to crawl around at that speed for a full circuit.

 

I have to say that my three steamers (Blink Bonny, William Whitelaw and Trigo) didn't show the even slightest interest in pulling the six coaches plus the dummy HST car at the same low speed as the HST. Even at speed setting '10' Trigo would stop and wheelspin frequently. However the steamers weigh a bit less than the HST so maybe they'd benefit from a bit of extra weight (and maybe a bit of wheel cleaning, too).

 

Finally, I have to say that if the TV series 'Hornby: A Model World' is even faintly true to reality then I think the idea that Hornby would settle for a 4-coach HST as a 'maximum' because "TT:120 is for smaller spaces" doesn't really hold water. There is no evidence for them thinking that and on the TV series they seemed just as enthusiastic to see a loco pulling a realistic rake of carriages or wagons at speed as the rest of us.

 

Edited March 29 by Porfuera

[Michanglais]

7 minutes ago, Porfuera said:

 

Hi Michael,

 

I'm sorry to say that you might want to return your HST to Hornby for them to take a look at it if fitting it with DCC doesn't cure its problems (and I'm also doubtful that it would cure it but it must be worth a try).

 

After seeing your post I thought I'd give mine a test as I currently have a running-in loop of track on my dining room table (much to the delight of the Domestic Authority). The loop is a full circle of Tillig bedding track of radius 396 (so equal to Hornby's R4) plus only four 166mm straights, laid out with two straights per side (so the circuit is an oval rather than a 'square').

 

I don't have any BG Mk3s (they're not out yet) so I tried my HST set with three unlit Pullmans from the Scotsman set and three Mk1 from the Easterner. My HST set is DCC and it came pre-fitted.

 

The 'train' was long enough to cover almost half of the circuit so a considerable amount of it is always on a curve yet it pulled away at the lowest speed setting (i.e. '1' on the app) and continued crawling at that speed without any problems for a full circuit.

 

Then I noticed that you said you were running 8 coaches rather than the six that I had. The only bogie vehicles I had left to try were three Arnold container wagons so I added those to give a total of 9 vehicles plus the dummy power car. I think the Arnold wagons are a bit heavier than the coaches, plus the 'train' now covered more than half of the circuit, so it was even more demanding. However, the result was the same with the HST starting at '1' and continuing to crawl around at that speed for a full circuit.

 

I have to say that my three steamers (Blink Bonny, William Whitelaw and Trigo) didn't show the even slightest interest in pulling the six coaches plus the dummy HST car at the same low speed as the HST. Even at speed setting '10' Trigo would stop and wheelspin frequently. However the steamers weigh a bit less than the HST so maybe they'd benefit from a bit of extra weight (and maybe a bit of wheel cleaning, too).

 

Finally, I have to say that if the TV series 'Hornby: A Model World' is even faintly true to reality then I think the idea that Hornby would settle for a 4-coach HST as a 'maximum' because "TT:120 is for smaller spaces" doesn't really hold water. There is no evidence for them thinking that and on the TV series they seemed just as enthusiastic to see a loco pulling a realistic rake of carriages or wagons at speed as the rest of us.

 

 

Glad to hear your HST seems to be behaving!

 

I've sent an inquiry to Technical Services to see what they think. Oh, I also tried it on DCC - same issues as with DC. 

 

I'm wondering whether there is an issue with the gears and not all wheels are being driven. I guess I could test that quite easily myself...

 

Going back to your test, one thing I've noticed is that the Mk3s aren't as free running as the Mk1s or Pullmans. Well, that's my experience, anyway. Maybe it's the coaches that are to blame. I've currently got all of my other TT coaches boxed up ready for a house move but now you've related your experiences I'm tempted to unpack them and give that a go.

 

Thanks for your detailed reply!

 

Cheers,

Michael

 

[Michanglais]

Curiosity got the better of me and I unpacked a rake of seven Mk1s.

 

My HST is now happily purring around with the Mk1s and the dummy at the rear. Functioning fine at all speeds.

 

Notably, the Mk1s are much freer rolling than the Mk3s so I'm thinking the Mk3s are what's causing the issue. Perhaps I need to apply some graphite to the axle points on the Mk3s or, even more drastically, loosen the axle 'boxes' on a few coaches so that there's less drag.

 

Bit of a pain but worth a try, I guess...

 

[Porfuera]

15 minutes ago, Michanglais said:

Curiosity got the better of me and I unpacked a rake of seven Mk1s.

 

My HST is now happily purring around with the Mk1s and the dummy at the rear. Functioning fine at all speeds.

 

Notably, the Mk1s are much freer rolling than the Mk3s so I'm thinking the Mk3s are what's causing the issue. Perhaps I need to apply some graphite to the axle points on the Mk3s or, even more drastically, loosen the axle 'boxes' on a few coaches so that there's less drag.

 

Bit of a pain but worth a try, I guess...

 

That's interesting. No wonder mine was running freely - I didn't have the correct coaches for the test! Good to know that your power car is running OK, at least, and hopefully you'll get to the bottom of what's happening with the Mk3s.

 

I seem to recall that there was a problem with the early Mk1s where a stub of plastic was left on the underside of the coaches (IIRC it wasn't meant to be there - it was something to do with the assembly process and should have been removed) and this rubbed against the wheels but only when the coaches went around a curve.

 

It has since been fixed on the Mk1s but given that you were running a long formation on a loop of track could it be something like that? Maybe at some point you could you try the HST and the Mk3s on a straight length of track to see if they are OK on the straight and therefore whether it is something that only happens on curves?

 

And good luck with your house move - I hope it all goes smoothly!

[froobyone]

45 minutes ago, Michanglais said:

Curiosity got the better of me and I unpacked a rake of seven Mk1s.

 

My HST is now happily purring around with the Mk1s and the dummy at the rear. Functioning fine at all speeds.

 

Notably, the Mk1s are much freer rolling than the Mk3s so I'm thinking the Mk3s are what's causing the issue. Perhaps I need to apply some graphite to the axle points on the Mk3s or, even more drastically, loosen the axle 'boxes' on a few coaches so that there's less drag.

 

Bit of a pain but worth a try, I guess...

 

My single Mk3 so far obtained, also does not run as freely as I would have expected. Considering the Pullmans have additional drag due to the electrical contacts, they run so much cleaner and longer after a push. I did a side by side test and the Pullmans easily go half a coach further. Maybe the Mk3's need a little running in to free-up. I can't test this theory as I have no running track currently wired (pun half intended).

After examining the wheels, only one out out of the four is free running, The other three are being restricted somehow. I'm wondering if a little tickle of PTFE or silicone lubricant might give it some help. I'll test it at some point. 

I hope this is solvable as HSTs are the only reason I'm going to TT. :-/

Best

Dan

[Roy L S]

2 hours ago, Porfuera said:

 

Hi Michael,

 

I'm sorry to say that you might want to return your HST to Hornby for them to take a look at it if fitting it with DCC doesn't cure its problems (and I'm also doubtful that it would cure it but it must be worth a try).

 

After seeing your post I thought I'd give mine a test as I currently have a running-in loop of track on my dining room table (much to the delight of the Domestic Authority). The loop is a full circle of Tillig bedding track of radius 396 (so equal to Hornby's R4) plus only four 166mm straights, laid out with two straights per side (so the circuit is an oval rather than a 'square').

 

I don't have any BG Mk3s (they're not out yet) so I tried my HST set with three unlit Pullmans from the Scotsman set and three Mk1 from the Easterner. My HST set is DCC and it came pre-fitted.

 

The 'train' was long enough to cover almost half of the circuit so a considerable amount of it is always on a curve yet it pulled away at the lowest speed setting (i.e. '1' on the app) and continued crawling at that speed without any problems for a full circuit.

 

Then I noticed that you said you were running 8 coaches rather than the six that I had. The only bogie vehicles I had left to try were three Arnold container wagons so I added those to give a total of 9 vehicles plus the dummy power car. I think the Arnold wagons are a bit heavier than the coaches, plus the 'train' now covered more than half of the circuit, so it was even more demanding. However, the result was the same with the HST starting at '1' and continuing to crawl around at that speed for a full circuit.

 

I have to say that my three steamers (Blink Bonny, William Whitelaw and Trigo) didn't show the even slightest interest in pulling the six coaches plus the dummy HST car at the same low speed as the HST. Even at speed setting '10' Trigo would stop and wheelspin frequently. However the steamers weigh a bit less than the HST so maybe they'd benefit from a bit of extra weight (and maybe a bit of wheel cleaning, too).

 

Finally, I have to say that if the TV series 'Hornby: A Model World' is even faintly true to reality then I think the idea that Hornby would settle for a 4-coach HST as a 'maximum' because "TT:120 is for smaller spaces" doesn't really hold water. There is no evidence for them thinking that and on the TV series they seemed just as enthusiastic to see a loco pulling a realistic rake of carriages or wagons at speed as the rest of us.

 

I did say: - "If the coaches and dummy car are all suitably free-running, it does beg the question was the power car designed to run with a full 8 car set? ".. 

 

It would now seem to have been established that the Mk3s are not free running so that is clearly a contributory factor and would seem to be a design or manufacturing issue. In terms of what Hornby do or do not intend for TT120, most of the launch material shows locos and three coaches on a relatively small double-track layout, and it was Simon Kohler in interviews who was singing TT120s benefits in a smaller space and speaking of a target market that is new. I have so far only seen an HST and four Mk3s in promotional material not a full set anywhere, so my question did appear a fair one. I do have some "skin" in the TT120 game still (just) and want it to succeed but I am not so "evangelical" as to promote it blindly or ignore faults and pitfalls as some appear top be.

 

 

[Porfuera]

3 minutes ago, Roy L S said:

"...it does beg the question was the power car designed to run with a full 8 car set? ".. 

 

I know you have some TT:120 but that thought wouldn't even have crossed my mind - not designed to run anything less than an 8-car set, not these days.

 

After all, they are selling 8 differently-numbered coaches in two of the liveries - presumably they expect some people to buy all of them so why would they deliberately design it so that the powered car couldn't pull them all together?

[Roy L S]

22 minutes ago, Porfuera said:

 

I know you have some TT:120 but that thought wouldn't even have crossed my mind - not designed to run anything less than an 8-car set, not these days.

 

After all, they are selling 8 differently-numbered coaches in two of the liveries - presumably they expect some people to buy all of them so why would they deliberately design it so that the powered car couldn't pull them all together?

That eight differently numbered coaches are being made is a fair comment and you would think it might point towards the intention of a full length train for those with space, but something has clearly gone awry if the reality now hitting consumers like Michael is that the coaches are too "draggy" to allow that or if that is how they are intended to be (seems doubtful) the power car is not sufficiently capable.

 

I guess the big question is are all the TT120 Mk3s like it? If it turns out they are, pointing to an issue in manufacturing or assembly  then there are likely to be a fair few disappointed purchasers if Michael's experience is typical. It will be interested to know what others' experiences have been, and if widespread what Hornby have to say, assuming they tested the power-car to and beyond the expected maximum load with these coaches.

 

To be fair, the issue isn't unique to Hornby or TT120, immediately coming to mind in N are the Rapido Conflat Ps and NGS Ferry Vans, both having similar issues and manging to get past QC into the hands of consumers, and I recall the Revolution Mk5s also had some issues.

 

Roy

[woodenhead]

It's not the first time Hornby have turned out coaches that are not free running and purchasers have had to do things to make them run better.  And as indicated others manufacturers have too, it could be a bad batch or simply they've gotten it wrong with the bogies and later releases may be better.

[Porfuera]

29 minutes ago, Roy L S said:

That eight differently numbered coaches are being made is a fair comment and you would think it might point towards the intention of a full length train for those with space, but something has clearly gone awry if the reality now hitting consumers like Michael is that the coaches are too "draggy" to allow that or if that is how they are intended to be (seems doubtful) the power car is not sufficiently capable.

 

I guess the big question is are all the TT120 Mk3s like it? If it turns out they are, pointing to an issue in manufacturing or assembly  then there are likely to be a fair few disappointed purchasers if Michael's experience is typical. It will be interested to know what others' experiences have been, and if widespread what Hornby have to say, assuming they tested the power-car to and beyond the expected maximum load with these coaches.

 

To be fair, the issue isn't unique to Hornby or TT120, immediately coming to mind in N are the Rapido Conflat Ps and NGS Ferry Vans, both having similar issues and manging to get past QC into the hands of consumers, and I recall the Revolution Mk5s also had some issues.

 

Roy

 

But none of those things are designed that way. As I said before, these days you wouldn't get away with deliberately designing an HST to run as a 4-car set. It would be the same if someone decided to use a generic chassis for a number of steam locos - that would be unthinkable, and to me a 4-car HST would be the same, regardless of the fact that most people won't be able to run an 8-car set anyway.

 

And as I mentioned already, Hornby had problems with the Mk1s and these were easily sorted. I like to think positively and say that any problem with the Mk3s would be equally minor. These things go through a lot of testing and hopefully any problem will be an assembly error rather than a fundamental design issue.

Edited March 29 by Porfuera

[Baz657]

This was mine the day it arrived.

 

https://youtu.be/0J9G5egPFJo

Edited March 29 by Baz657

[GenericRMWebUsername]

1 hour ago, Baz657 said:

This was mine the day it arrived.

 

https://youtu.be/0J9G5egPFJo

Your HST looks great! And your video's title was sadly all too relatable... 😅

[moawkwrd]

16 hours ago, Roy L S said:

It would now seem to have been established that the Mk3s are not free running so that is clearly a contributory factor and would seem to be a design or manufacturing issue.

 

Statements like that aren't particularly helpful. We've so far got one person with some MK3s that aren't free running (and no idea if that's all of them or just one) and a video above of 8 running perfectly fine.

 

At this point there's nothing to suggest that it's a design or manufacturing issue as defects occur in small quantities even with the best designed products.

[Roy L S]

4 hours ago, moawkwrd said:

 

Statements like that aren't particularly helpful. We've so far got one person with some MK3s that aren't free running (and no idea if that's all of them or just one) and a video above of 8 running perfectly fine.

 

At this point there's nothing to suggest that it's a design or manufacturing issue as defects occur in small quantities even with the best designed products.

 

I am not sure my comments were intended to be "helpful" or unhelpful, they were observations based on what had been reported at that point, and actually @Michanglais and @froobyone who have both reported issues with stiff running Mk3s so far. No, we don't know if it is a single coach out of Michael's 8 purchased, but given the power car would cope with three but not five it does suggest that the problem is with more than one coach, I am sure @Michanglais will say if otherwise. 

 

Let's wait and see what consensus is once more of the coaches land with purchasers.

 

Roy

[Michanglais]

1 hour ago, Roy L S said:

 

I am not sure my comments were intended to be "helpful" or unhelpful, they were observations based on what had been reported at that point, and actually @Michanglais and @froobyone who have both reported issues with stiff running Mk3s so far. No, we don't know if it is a single coach out of Michael's 8 purchased, but given the power car would cope with three but not five it does suggest that the problem is with more than one coach, I am sure @Michanglais will say if otherwise. 

 

Let's wait and see what consensus is once more of the coaches land with purchasers.

 

Roy

 

I can confirm that all of my Mk3s have the same characteristics - all wheels correctly situated, all wheels turning freely. Well, freely... if you try to spin the wheels they stop immediately. My Mk1s keep spinning. 

One other thing I forgot to mention - I used magnetic couplings to have corridor-to-corridor operations. However, while the Mk1s remain close coupled when running, the Mk3s 'stretch' the kinematic mechanism to its limit and that leaves quite distinct gaps between the coaches. Obviously Mk3s will be heavier but notably, I also run Continental N using the same couplers. The coaches are only a couple of centimetres shorter than a Mk3 and are just as heavy in the hand but they don't exhibit this 'stretching' phenomenon.

 

Interesting...

 

[Ravenser]

Bearing reamers for 9mm and 16.5mm gauge are available from DCC Concepts . Does anyone know of a source for an equivalent 12mm gauge device? Something might be available in germany

[D9020 Nimbus]

A number of Hornby TT120 wagons are a little less than free-rolling in my experience. Though sometimes stock can be too free rolling. In my experience, I've only encountered one N gauge loco that can't haul a prototypical load — the old Minitrix Ivatt 2-6-0. These are, I believe, notorious for this issue. I'm not sure why—it's heavier than most locos, so perhaps it's the weight distribution that's wrong.

 

I don't have enough room to test the haulage powers of the OO locos I have, which is why my main interests are OO9/HOe, N and TT120.

[GrumpyPenguin]

1 hour ago, Michanglais said:

all wheels turning freely. Well, freely... if you try to spin the wheels they stop immediately. My Mk1s keep spinning.

IMHO there lies the problem.

 

Would it be possible to swop some wheelsets over just to seed if it makes any difference ?

 

Otherwise, I would try a tiny drop of lubticant on the bearing, but check first that whatever you use is suitable for the bearing surfaces - maybe a product from LeBelle would do the trick.

[Roy L S]

15 minutes ago, GrumpyPenguin said:

IMHO there lies the problem.

 

Would it be possible to swop some wheelsets over just to seed if it makes any difference ?

 

Otherwise, I would try a tiny drop of lubticant on the bearing, but check first that whatever you use is suitable for the bearing surfaces - maybe a product from LeBelle would do the trick.

I am not sure I would want to use a liquid lubricant on pinpoint bearings personally, it is likely to attract dirt and in time jam the wheels up more over time. If any kind of "lubricant" is to be used I would suggest graphite in the bearing pocket itself. Of course the other alternative that has been mentioned would probably be to carefully ream out the bearing holes slightly with a purpose made axle-reamer. Should someone expect to need to do this on a brand new model? No in an ideal world probably not and it would invalidate any warranty but it would be a potential solution as an alternative to returning them. It is interesting that Michael has identified the kinematic couplings going to full stretch, and to me this is another indication of overtight wheel bearings that are overpowering their spring mechanisms. 

[Steamport Southport]

Do these have lights or connections to fit lights?

 

I have found that some 00 coaches need running in a bit from new if fitted, otherwise they drag a bit as the pick ups act like a brake. Usually fine after a bit of use.

 

 

 

Jason

Edited March 30 by Steamport Southport

[natterjack]

Tight wheels may be due to slightly over-length axles in which case a couple of file or stone strokes at each end could be a quick and simple solution. It has worked for me in OO.

[Porfuera]

Cross-post from the main Hornby TT:120 thread, but the BG and GWR Mk3 coaches are showing as in stock.

 

Did anyone get any further in finding the reason for the dragging wheels on the Exec Mk3s? Was it tight axle points in the bogie frames or something else like the wheel flanges rubbing on the underside of the coach or somewhere, which has been seen before and which also seems to be happening with the some of the new BR 50-foot brakes?

 

I haven't seen it reported anywhere else so I'm hoping it is an assembly issue rather than a design problem.

 

Edited April 7 by Porfuera

[Porfuera]

A couple of hours ago I received four emails saying that my four BG Mk3 pre-orders have arrived. My credit card has been debited as well.

Edited April 12 by Porfuera